Firestop collar

ABSTRACT

A metal casing strip for a fire collar to be arranged around a duct has a line of succesive tongues and cutouts in the longitudinal direction of the strip. The tongues and cutouts are arranged in the strip in an alternating fashion. The tongues are bendable out of the surface of the casing strip such that in use, when the casing strip is arranged around a pipe such that two end regions overlap, an outwardly bended tongue from the one end region is inserted in a cutout of the overlapping other end region and folded over the edge of the cutout to retain the casing strip in the closed collar shape.

FIELD OF THE INVENTION

The present invention relates to the field of fire collars. Fire collarsare typically applied around pipes, cable ducts or other ducts which arepassed through a support surface such as a wall, ceiling or the like.The collar includes a layer of intumescent material within a casing. Incase of heat the intumescent material swells. The casing retains theswelling intumescent material and causes the intumescent to apply apressure on the pipe or other duct. If the pipe or duct is of plasticsmaterial the pipe or duct may collide under the pressure of the swellingintumescent. If the pipe is made of metal the space around the pipe isfilled with intumescent. Thereby the passage through the wall or ceilingis closed off effectively for heat and smoke. The collar can be fixed inposition on the wall, by some suitable attachement means.

From the company 3M is known a Fire Barrier FS-195+ Strip/Wrap which isa strip of intumescent material which at the job site is cut to lengthby a fitter and then wrapped around a pipe or conduit. From 3M is alsoknown a metal casing strip under the name of Fire Barrier RC-1Restricting Collar, which is also cut to length at the job site by thefitter and then wrapped around the intumescent strip already wrappedaround the pipe. The metal casing is held in the closed state by aseparate metal string laid around the casing. The metal casing stripRC-1 has attachment tabs on one longitudinal side, which attachment tabsare bended outwardly by the fitter such that the can be placed against asupport surface. The attachment tabs each have a hole through which ascrew can be inserted to attach the metal casing to the support surface.In U.S. Pat. No. 4,951,442 is disclosed a similar casing, but with apredetermined length.

In U.S. Pat. No. 5,103,609 is disclosed a fire collar which is adaptedfor a predetermined pipe diameter. The fire stop collar has a casing anda intumescent layer attached thereto. The fire stop collar furthermorehas brackets which are attached to a wall or the like and which arecoupled to the casing by lips extending through an aperture in thebrackets, which lips are folded so as to couple the bracket to thecasing.

EP 982 522 A2 discloses a fire collar with a metal casing and bracketsthat are coupled to the casing and attached to a wall.

EP 1 181 481 discloses another fire collar, in which an intumescentlayer is attached to a metal casing strip, e.g. by an adhesive. The firecollar has brackets which are coupled to the casing so as to attach thecollar to a wall.

The present invention has for an object to provide an assembly for afire collar which provides a more convenient use.

SUMMARY OF THE INVENTION

The object is achieved by a metal casing strip for a fire collar to bearranged around a pipe or other duct, wherein the casing strip has aline of successive tongues and cutouts in the longitudinal direction ofthe strip. The tongues and cutouts are arranged in the strip in analternating fashion. The tongues are bendable out of the surface of thecasing strip such that in use, when the casing strip is arranged arounda pipe or other duct such that two end regions overlap, an outwardlybended tongue from the one end region is inserted in a cutout of theoverlapping other end region and folded over the edge of the cutout toretain the casing strip in the closed collar shape.

The invention also relates to a combination of a metal casing strip fora fire collar to be arranged around a pipe or other duct and anattachment bracket for attaching the casing strip to a support surface.The casing strip has a line of succesive tongues and cutouts in thelongitudinal direction of the strip, which tongues and cutouts arearranged in the strip in an alternating fashion. The tongues arebendable out of the surface of the casing strip such that in use, whenthe casing strip is arranged around a pipe or other duct such that twoend regions overlap, an outwardly bended tongue from the one end regionis inserted in a cutout of the overlapping other end region and foldedover the edge of the cutout to retain the casing strip in the closedcollar shape. Above the free end of the tongue is a clearance space andthe bracket has an end edge with at least one tooth provided on it,which tooth is insertable through the clearance space, such that thetooth engages behind the tongue, whereby, when the bracket is moveddownwards, the tongue is bended out of the surface of the casing strip.

The casing strip according to the invention allows for an easy wrappingaround a pipe or other duct and securing it in the wrapped state withoutthe need for additional parts to keep the collar closed.

Another aspect of the invention relates to a combination of a metalcasing strip for a fire stop collar and an attachment bracket forattaching the casing strip to a support surface, said metal casing striphaving successive segments with a weakening line between successivesegments, which metal casing strip in use is severed at a weakening lineto bring the casing strip to the desired length to allow it to bewrapped around a pipe or other duct, said bracket having a side edge aswell as holding and positioning means for holding the strip, wherein theside edge of the bracket is positioned over one of the weakening linesand the strip can be bended and broken along said side edge of thebracket when in use the positioning means of the bracket are incooperation with the positioning means of the casing.

The bracket according to the invention is used as a tool to brake offthe casing strip at the desired length for wrapping around a duct.

Preferred embodiments of the invention are defined by the dependentclaims.

The invention will be described in more detail in the followingdescription with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a view in perspective of a part of a casing strip accordingto the invention;

FIG. 2 shows a side view of the casing strip of FIG. 1;

FIG. 3 shows a sectional view of the casing strip of FIG. 1 at thelocation of a weakening line;

FIG. 4 shows in a perspective view an attachment bracket to attach thecasing strip of FIG. 1 to a support surface;

FIG. 5 illustrates the use of the bracket of FIG. 4 as a tool forsevering the strip of FIG. 1 to the desired length;

FIG. 6 illustrates the use of the bracket of FIG. 4 as a tool forbending tongues in the strip outwardly;

FIG. 7 a and FIG. 7 b show in different views in perspective how thebracket of FIG. 4 is assembled with the casing strip of FIG. 1;

FIG. 8 a and FIG. 8 b show in different views in perspective how thebracket of FIG. 4 is assembled with the casing strip of FIG. 1;

FIG. 9 illustrates how the assembled combination of FIG. 8 is wrappedaround a pipe; and

FIG. 10 shows how the assembled combination of FIG. 9 is mounted aroundthe pipe and attached to a support surface.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 is shown a length of a metal casing strip 1 for forming acasing for a fire collar. The casing strip 1 is preferably made of steelwith a thickness of for example 0.5 mm and is generally flat as can beseen in FIG. 2.

The casing strip 1 comprises successive strip segments 2. Between thestrip segments 2, a weakening line 3 is provided which allows the casingstrip 2 to be severed at a desired length. The weakening line 3 ispreferably formed by a groove in the strip material as is shown in FIG.3. The weakening line in FIG. 3 is a generally V-shaped groove with adepth d which is approximately half of the thickness of the strip, thusfor example 0.25 mm. The width w of the groove at the surface of thestrip 1 is for example corresponding to the thickness t of the strip 1.

The strip 1 has an upper longitudinal edge 4 which in use is remote froma support surface (see FIG. 10) and a lower longitudinal edge 5 which inuse faces the support surface.

At the upper edge 4 inwardly bended tabs 6 are formed, the function ofwhich will become clear below. Each segment 2 has two spaced apartinwardly bended tabs 6. However, there may be also another number ofbended tabs 6.

At a distance from the lower edge 5 a line positioning protrusions 7 isformed. The positioning protrusions 7 are formed as bulges as is bestvisible in the side view of FIG. 2. Each segment has preferably twopositioning protrusions 7 as is shown, but may also have another numberof positioning protrusions.

The casing strip 1 has between the upper edge 4 and the line ofpositioning protrusions 7 a line of regularly spaced apart tongues 8 andregularly spaced apart holes 9. The tongues 8 and the holes 9 arearranged alternately in the line.

In the preferred embodiment shown in the figures, the tongues 8 have aninverted U-shaped cutout 10 around them. Each tongue 8 is positionedsuch that one of the legs 10 a of the U-shaped cutout is adjacent aweakening line 3. The tongues 8 are thus attached only at their lowerend and can be bended out of the generally flat surface of the casingstrip 1.

The holes 9 have a width which is slightly greater than the width of thetongues 8.

In FIG. 4 is shown an attachment bracket 11 which is adapted tocooperate with a casing strip 1 as is described above.

The bracket 11 is made of a metal strip bended to generally an L-shapewith a first leg 12 and a second leg 13. The first leg 12 engages on asupport surface when mounted (see FIG. 10). The second leg 13 engages inthe mounted state on the outer side of the casing strip 1 (see FIG. 10).

The second leg 13 has an upper end 14 where two hook members 15 arearranged which extend transversely with respect to an inner leg surface16.

At a lower end 17 of the second leg 13 a lug 18 is bended out of thesurface 16 of the second leg 13. The lug 18 extends substantiallyparallel to the inner leg surface 16 of the second leg 13, at a distancewhich substantially corresponds to the thickness of the casing strip 1,thus for example about 0.5 mm. The lug 18 is located in the middle ofthe leg 13 seen in the width direction of the leg 13.

In the lug 18 is provided a recess, preferably a hole 19 as is shown inFIG. 4. The hole 19 is located at a height such that when a casing strip1 with its lower region is inserted between the lug 18 and the innersurface 16 of the second leg (see FIGS. 7 and 8), the protrusions 7 areat the same height as the hole 19. The hole 19 has a diameter such thata positioning protrusion 7 fits in it. This will be elucidated furtherbelow.

The first leg 12 has a hole 20 in it for passing through an attachmentelement such as a screw such that the bracket can be attached to asupport surface (see FIG. 10). The hole 20 has an oblong shape to allowfor mounting flexibility.

The first leg 12 of the bracket 11 has a free end which is provided withthree teeth 21, 22. The two outer teeth 21 are longer than the middletooth 22. The mutual distance between the outer teeth 21 correspondswith the mutual distance between the bendable tongues 8. The width andthe thickness of the outer teeth 21 is such that it can be inserted inthe portion of the cutout 10 above the tongues 8 as will be describedfurther on in the description.

The use of the above described casing strip 1 and accompanying bracket11 will be described below with reference to FIGS. 5-10.

A fire collar is commonly mounted around a pipe or another duct whichextends through a passage in a wall, ceiling or floor. The fire collarabuts the wall, the floor or the ceiling such that when in case of afire or extreme heat, the intumescent material swells and closes of thepassage through the wall, floor or ceiling. When a fitter is mounting afire collar around a pipe, he will first wrap a layer of intumescentmaterial around the pipe. In FIG. 9 the pipe is indicated with referencenumeral 23 and the layer of intumescent material is indicated withreference numeral 24. The intumescent layer 24 is arranged to abut thesurface of the support surface 25, i.e. a wall, floor or ceiling.

After the intumescent layer has been applied around the pipe, the casingcan be arranged around the intumescent. The casing is formed by wrappinga length of casing strip around the intumescent material.

The casing strip 1 is preferably delivered on a roll. A suitable lengthof strip can be cut such that it fits around the intumescent layer 24.In FIG. 5 it is shown how the strip 1 can be brought to the desiredlength. The bracket 11 is positioned with its inner surface 16 againstthe outer surface of the casing strip 1. Thereto the lug 18 is movedbeyond the lower edge 5 of the strip 1 and moved upwards such that thelug 18 grips behind the edge 5 as is shown in FIGS. 7 a and 7 b. Thebracket is then moved upwards until the lug with an upper edge thereofengages a protrusion 7. The lug 18 is resiliently deformed away from thesecond leg until the protrusion 7 snaps into the hole 19 of the lug 18.At the same time the hook members 15 on the upper end of the second leg13 of the bracket 11 engage in the intermediate spaces between theinwardly bended tabs 6 on the upper end 4 of the casing strip 1 as isshown in FIG. 5. The bracket 11 is now attached to the strip 1.

Each strip segment 2 has two protrusions 7. When, in FIG. 5 the leftprotrusion 7 (seen from the outer side of the casing strip 1) of asegment 2 is located in the hole 19 in the lug 18, the right side edgeof the second leg 13 lies over the right weakening line 3 of that samesegment 2. The fitter can hold the bracket at the first leg 12 with onehand and move the strip portion right thereof here and forth with theother hand. Thereby the strip 1 will brake at the weakening line 3 alongthe side edge of the second leg 13 of the bracket 11.

After the casing strip 1 has been brought to the desired length, thebracket 13 is released from the casing strip 1 again. Next, the twoouter teeth 21 on the first leg 12 of the bracket 11 can be inserted inthe portion of the cutout 10 above the tongues 8 of the outermost twosegments 2 at one of the strip ends. Then the bracket 11 can beswivelled upwards to a position as is shown in FIG. 6 such that theteeth 21 engage behind the tongues 8. Next, the bracket 11 can beswivelled downwardly such that the tongues 8 are bent outwardly to aposition which is best visible in FIG. 7 a. The central tooth 22functions as a support point around which the swivelling takes placeduring this movement.

Now the bracket 11 can be released again from the cut-outs 10 and bearranged in a mounting position on the casing strip 1. Thereto the lug18 is moved again beyond the lower edge 5 of the strip 1 and movedupwards such that the lug 18 grips behind the edge 5 as is shown inFIGS. 7 a and 7 b. The bracket 11 is then moved upwards until the lugwith an upper edge thereof engages a protrusion 7. This time theprotrusion 7 on the right (seen from the outer side) of the segment 2 isengaged. The lug 18 is resiliently deformed away from the second leg 13until the protrusion 7 snaps into the hole 19 of the lug 18. At the sametime the hook members 15 on the upper end of the second leg 13 of thebracket 11 engage in the intermediate spaces between the inwardly bendedtabs 6 on the upper end 4 of the casing strip 1 as is shown in FIG. 5.The bracket 11 is now attached to the strip 1. In this way a pluralityof brackets 11, for example three, can be attached to the casing strip1.

The assembly of the casing strip 1 with the attachment brackets 11 cannow be arranged around the intumescent layer 24 wrapped around the pipe23 as is illustrated in FIG. 9. The casing strip 1 is brought intoabutment with the support surface 25. The casing is closed by bringingthe end regions of the strip towards each other such that the endregions overlap. The outwardly bended tongues 8 at one end of the casingstrip 1 are inserted in the openings 9 of the overlapping opposite endregion of the strip (see FIG. 10 left tongue 8), after which the tongues8 are bended downwardly over the edge of the hole 9 (see FIG. 10 righttongue 8) to retain the casing in the closed state.

The brackets 11 can now be attached to the support surface 25 by meansof screws 26 which are passed through the holes 20 in the first legs 12of the brackets 11, as is illustrated in FIG. 10. Thereby the firecollar is retained in position around the pipe 23 against the supportsurface 25.

1. A fire stop collar assembly comprising: a metal casing strip havingan inner and an outer surface and having successive segments with aweakening line between successive segments, said metal casing strip inuse being severed at a weakening line to bring the casing strip to thedesired length to allow it to be wrapped around a pipe or other duct,the metal casing furthermore having positioning members; a severing toolhaving a side edge as well as a holding member constructed and arrangedto hold the casing strip and to cooperate with the positioning member ofthe casing; wherein, when in use the holding member of the severing toolis in cooperation with the positioning member of the casing, said sideedge of the severing tool is positioned in engagement with one of theinner or outer surface of the casing strip adjacent one of the weakeninglines and the strip can be bended and broken at said weakening linealong said side edge of the bracket.
 2. The assembly according to claim1, wherein the severing tool is an attachment bracket adapted to attachthe casing strip to a support surface.
 3. The assembly according toclaim 2, wherein the bracket has a general L-shape, comprising a firstleg, which, in a mounted state, engages the support surface, and asecond leg, which, in use, is positioned on the outer surface of thecasing.
 4. The assembly according to claim 3, wherein the casing striphas a lower longitudinal edge, which in use is turned to the supportsurface, wherein the holding member of the bracket comprise a lug spacedapart from the second leg, which in use engages around the lower edge ofthe casing strip and is positioned on the inner surface of the casing.5. The assembly according to claim 4, wherein, seen in the widthdirection of the bracket, the lug is located in the middle of thebracket.
 6. The assembly according to claim 4, wherein the lug is formedas a tongue punched from the second leg.
 7. The assembly according toclaim 4, wherein the lug has a positioning recess provided in it andwherein the strip of casing material has positioning protrusions on theinner surface thereof, wherein the recess in the lug is adapted toreceive one of the protrusions, wherein, when one of the protrusions inthe strip is received in the recess in the lug, the side edge of thesecond leg is located at a weakening line in the strip, such that thestrip can be bended and broken along the edge of the second leg.
 8. Theassembly according to claim 1, wherein the casing strip has an upperlongitudinal edge, which in use is remote from the support surface,wherein at said upper edge inwardly bended tabs are provided.
 9. Theassembly according to claim 8, wherein the bracket at the end thereofwhich in a mounted state is remote from the support surface, has holdingand positioning members formed as one or more inwardly extending hookmembers which are dimensioned to engage in the mounted state in anintermediate space between said inwardly bended tabs.
 10. The assemblyaccording to claim 2, wherein the casing strip has a line of successivetongues and cutouts in the longitudinal direction of the strip, whichtongues and cutouts are arranged in the strip in an alternating fashion,wherein the tongues are bendable out of the surface of the casing stripto allow in use, when the casing strip is arranged around a pipe suchthat two end regions overlap, a that a tongue is bended outwardly fromthe one end region and is inserted in a cutout of the overlapping otherend region and folded over the edge of the cutout to retain the casingstrip in the closed collar shape.
 11. The assembly according to claim10, wherein in each segment one tongue and one cutout is provided. 12.The assembly according to claim 11, wherein above the free end of thetongue is a clearance space and wherein the bracket has an end edge withat least one tooth provided on it, which tooth is insertable through theclearance space, such that the tooth engages behind the tongue, wherebywhen the bracket is moved downwards the tongue is bended out of thesurface of the casing strip.
 13. The assembly according to claim 12,wherein the bracket has two teeth which are each insertable through theclearance space at two successive tongues.
 14. The assembly according toclaim 13, wherein the bracket between said two teeth has an intermediatetooth with a smaller length than said two teeth.
 15. The assemblyaccording to claim 1, wherein the weakening line is defined by a groovein the casing strip.
 16. A fire stop collar assembly comprising a metalcasing strip, a separate strip of intumescent material and an attachmentbracket adapted to attach the casing strip to a support surface, saidstrip of intumescent material being adapted to be wrapped around a pipeor other duct, said metal casing strip having an inner and an outersurface, wherein the inner surface in use is arranged against the stripof intumescent material that is wrapped around the pipe or other duct,and said casing strip having successive segments with a weakening linebetween successive segments, said metal casing strip in use beingsevered at a weakening line to bring the casing strip to the desiredlength to allow it to be wrapped around the intumescent strip which isarranged around the pipe or other duct, the metal casing furthermorehaving positioning members, said bracket having a side edge as well as aholding member constructed and arranged to hold the casing strip and tocooperate with the positioning member of the casing, wherein, when inuse the holding member of the bracket is in cooperation with thepositioning member of the casing, said side edge of the bracket ispositioned in engagement with one of the inner or outer surface ofcasing strip adjacent one of the weakening lines and the strip can bebended and broken at said weakening line along said side edge of thebracket.
 17. A combination of a metal casing strip for a fire stopcollar and an attachment bracket adapted to attach the casing strip to asupport surface, said metal casing strip having successive segments witha weakening line between successive segments, which metal casing stripin use is severed at a weakening line to bring the casing strip to thedesired length to allow it to be wrapped around a pipe or other duct,said bracket having a side edge as well as holding and positioning meansfor holding the strip, wherein the side edge of the bracket ispositioned over one of the weakening lines and the strip can be bendedand broken along said side edge of the bracket when in use thepositioning means of the bracket are in cooperation with the positioningmeans of the casing.